authorities say the two suspects jahar and tamerlan tsarnaev are brothers of chechen ethnicity. the older brother has been shot and killed but the younger brother, jahar is on the run from police. police say the 19-year-old is armed with explosives. watertown massachusetts and other surrounding areas in boston are on lock down. s.w.a.t. teams and police going door to door looking for remaining suspect. >> we have several other new leads just developing and we're working on that. >> the fbi leased more pictures of the alleged trift along with a new wanted poster. >> they can wait him out in a way. he's going show himself at some point. they'll see him if he tries to move. i think that is the hope. >> thursday night a surveillance camera captures this image matching the man identified just hours before as suspect two. later police say the brothers ambushed a campus police officer and m.ti, killing and after car jacking a mercedes suv. the uncle says he hasn't been in touch with nephews for years but urged his sur are vifing nephew to surrender. >> jahar if you're alive turn yourse